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2 Sheets-Sheet 1.

(N0 Model.)

E. M. BIRDSALL. VALVE GEAR.

Patented May 14, 1889.

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E. M. BIRDSALL. VALVE GEAR.

No. 403,455. Patented May 14, 1889.

M550 rne'y,

UNITED .STATES PATENT OFFICE.

EDGAR M. BIRDSALL, OF BUFFALO, NEX/V YORK, ASSIGNOR TO MARY BIRDSALL, OF SAME PLACE.

VALVE-G EAR.

SPECIFICATION forming part of Letters Patent No. 403,455, dated May 14, 1889.

Application led December 29, 1888. Serial No. 294,929. (No model.)

To @ZZ whom t may concer/1,.-

Be it known that I, EDGAR M. BIRDSALL, of the city of Buffalo, in the county of Erie and State of New York, have invented new and useful Improvements in Valve-Gears for Steam- Engines, of which the following is a specification.

This invention relates to that class of valvegears for steam-engines in which the valveactuating eccentric is mounted upon the driving-shaft in such manner that its position with reference to the shaft can be readily changed or shifted so as to reverse the motion of the engine, or be adjusted so as to cut off the supply of steam to the cylinder-ports at any desired point of the stroke of the piston.

The object of my invention is to provide a simple, reliable, and inexpensive mechanism, whereby the position of the eccentric upon the shaft can be readily shifted or changed, as desired; and the invention consists in the peculiar construction of the parts, as will be hereinafter more fully described, and pointed out in the claims.

In the accompanying drawings, consisting of two sheets, Figure 1 is a longitudinalsectional elevation of my improved valve-gear applied to the crank-shaft of a steam-engine. Fig. 2 is a top plan view of the saine, partly in section. Fig. 3 is a cross-section in line Fig. l. Figs. 4 and 5 are cross-sections in line y y, Fig. 1, looking in opposite directions. Figs. 6 and 7 are cross-sections in lines .e ,e and w w, Fig. l, respectively. Fig. Sis a fragmentary horizontal section of the eccentric and connecting parts. Fig. 9 is a fragmentary horizontal section of the lever whereby the eccentric is shifted, showing' the worinpinion in elevation.

Like letters of reference refer to like parts in the several figures.

A represents the crank-shaft of a steam-en gine supported in hearings a a', and A represents the crank-disk secured to one end of the shaft A.

B represents the eccentric provided with a slot or elongated opening, l), through which the shaft A` passes.

C represents a supporting-disk secured to the shaft A. adjacent to the eccentric B, and to which the latter is movably attached by transverse V-shaped guides c, arranged in corresponding guide-ways, d d, formed on or secured to the adjacent side of the supporting disk C. This construction permits the eccentric B to loe shifted laterally on the disk C, so as to increase or diminish the degree of its eccentricity with reference to the shaft A and change its stroke accordingly.

E represents the eccentric-rod shown in dotted lines in Figs. 1 and 2, whereby motion is transmitted from the eccentric B to the engine-valve in the usual manner.

F represents a casing surrounding the shaft A on the inner side of the disk O, and secured to the latter by longitudinal screw-bolts f.

The casing F is divided longitudinally into two parts or shells, f f2. These shells are provided at their inner ends with inclined segmental ribs or faces f which lit into a corre'- spondingly-inclined seat or socket, f4, formed on the inner side of the disk C. rlhese in clined faces serve to tightly clamp the shells f f2 of the casing F against each other, and forni a rigid connection with the disk C when the shells are forced into the socket f4 by the screw-bolts j'. The inner ends of the shells f f2 are clamped together on one side of the casing F hy a transverse screw-loolt,f, The rim f5, forming thc socket f4, may be used as a pulley for the governor-helt.

The disk O and casing F are caused to re volve with the shaftA by means of a radial pin, g, secured to the shaft A and entering' an opening, g', formed in the meeting faces of .the shells f" f2, as clearly shown in Figs. 1 and 2. The pin g also serves to hold the parts against longitudinal movement on the shaftA.

G represents a shifting-lever arranged in a chamber, g2, formed in the casing F, on one side thereof, and swinging upon the pin g, as clearly shown in Figs. 1, 2, and 9. The inner arm, g3, of the lever G passes through an opening, h, formed in the disk O, and a recess, h', formed in the adjacent side of the eccentric B, and engages in an opening, h2, formed in a cylindrical block, Il', as clearly shown in Fie'. 8. The block II is seated in a circular opening,1', arranged in a crossbar,1,formed on the IOO eccentric B, so as be free to turn in its seat when the eccentric is shifted. The openings h h are made sufficiently large to allow of the requisite movement of the lever G in shifting the eccentric. The arm g3 of the lever G is free to move inwardly and outwardly in the block H when the eccentric is shifted,whereby binding of the parts is prevented.

I represents a worm-segment arranged at the inner end of the shifting -lever G, and which meshes with a transverse wormfpinion, J, mounted on the screw-bolt f within the casing F.

As clearly shown in Figs. 1, 2, 6, and 9, the wormpinion J consists of a cylindrical drum, j, which is provided on its circumference with several rows of projecting geanteeth, j. The teeth of the several rows are arranged in line with each other in the longitudinal direction of the drum and extend spirally around the circumference of the drum, so as to form a pinion which acts as a combined gear-wheel and worm.

K represents a longitudinally movable rack-bar which engages with the teeth j of the pinion J, and whereby the latter is rotated and the lever G shifted. The gear-rack K passes through an opening, 7c, in the outer end of the casing F, and is provided on its inner side with a key or feather, 7o', which engages in a groove or way, 7a2, formed in the shaft A, whereby'the rack-bar is compelled to rotate with the shaft A, while being free to move lengthwise on the shaft.

K represents a collar formed with or secured to the outer end of the raclebar K and encircling the shaft A, whereby the rack-bar is held against lateral displacement. The inner end of the rack-bar is bifurcated, as shown in Figs. 1 and 4, so that it can pass by the pin g.

L represents a longitudinally-movable rackbar arranged a short distance above the shaft A, and which is guided in its movements on a lug or way, Z, formed on the upper portion of the bearing a', on one side thereof, as clearlyshown in Fig. 7. The rack-bar L is attached to the collar K by a yoke, Z', which ts in an annular groove, Z2, formed in the periphery of the collar K.

m represents a stationary rack-bar secured to the upper side of the bearing a', opposite the rack-bar L, and n is a gear-wheel meshing on one side with the movable rack-bar L and on itsV opposite side with the fixed raclebar m. The gear -wheel 'n is supported upon shoulders or ledges n n?, formed 011 the rackbars L and m, and is held in place between the rackbars by a horizontal plate, n3, secured to the top of the stationary rack-bar.

p represents a short vertical shaft or stud secured t-o the gear wheel n, and which passes upwardly through a longitudinal slot or elongated opening, p', formed in the plate n3,

p2 represents'a shifting-rod, which is connected with the axlep of the gear-wheel nby an arm,^p3. The shifting-rod p2 is actuated in any ordinary and well-known manner.

Upon turning the wheel fn in one or the other direction by the rod p2 and arm p3 it is caused to travel inwardly or outwardly on the stationary rack-bar m, and thereby move the Wrack-bar L and the rack-bar K about twice the distance that the wheel n travels on the rack-bar m. This movement of the rack-bar K causes the pinion j to revolve and swing the shifting-lever G on its pivot, vand the latter in turn shifts the eccentric B on the shaft A. It will thus be seen that but a short movement of the rod p2 is required to shift the eccentric. i

The worm-pinion J is held against lateral movement between the shells f f2 of the casing F, and thereby serves to securely lock the eccentric in position after being shifted.

I claim as my inventionl. The combination, with the crank-shaft, of a supporting-disk secured to said shaft, an eccentric capable of movement on said support, a shifting-lever pivoted to said shaft, whereby-said eccentric is shifted, and aworm whereby said shifting-lever is actuated, substantially as set forth.

2. The combination, with the shaft A, the support C, secured thereto, and an eccentric capable of movement on said support, of a shifting-lever connected with said eccentric, a worm provided with gear-teeth whereby said shifting-lever is actuated, and a gear-rack whereby said worm is rotated, substantially as set forth.

3. The combination, with the shaft A, the support C, secured thereto, and the eccentric B, capable of movement on said support, of a movable block, H, seated in said eccentric, a shifting-lever movably attached to said `block and provided with a gear-segment, a worm en gagin g with said gear-segment, and a longitudinally -movable rack bar whereby said worm is rotated, substantially as set forth.

4. The combination, with the shaft A, the support C, -secured thereto, and an eccentric capable of. movement on said support, of a shifting-lever connected with said eccentric and provided with a gear-segment, a longitudinallymovabie rack bar, and a pinion provided with several rows of teeth arranged in line with each other lengthwise of the pinion and extending spirally around the same, substantially as set forth.

5. The combination, with the shaft A, the support C, and the eccentric B, arranged movl ably on said support, of a casing, F, surrounding the shaft, a pin, g, whereby said support and casing are secured to said shaft, a shifting-lever, G, pivoted to said pin, connected at one end to said eccentric and provided at its opposite end with a gear-segment, a combined worm and gear pinion, J, arranged in the casing F and engaging with said gearsegment, and a gear-rack whereby said wormpinion is rotated, substantially as set forth.

6. The combination, with the shaft A, the

IOO

IOS

IIO

support C, and the eccentric ]3, capable of movement on said support, of a tapering socket, f4, formed on said support, a casing, F, having beveled faces f3 engaging in said socket, screw-bolts f, whereby said bevelved faces are forced into said socket and said casing is secured to said support, a pin, g, whereby said casing is secured to said shaft, a worm-pinion, J, mounted in said casing, a shifting-lever, G, pivoted to said pin and engaging with said eccentric and with said worm-pinion, and a gear-rack, K, engaging with said worm-pinion, substantially as set forth.

7. The combination, with the shaft A, the disk C, and the eccentric B, supported on said disk and capable of movement thereon, of a casing, F, composed of sections f f2, surrounding said shaft and provided with inclined faces, a tapering socket formed on said disk and engaging over said inclined faces, screwbolts f, whereby the inclined ends of said sections are forced into said socket and against each other, a transverse screw, f,

centric-shifting mechanism mounted on said 3 5 shaft and rotating therewith, a stationary rack-bar, m, a movable rack-bar, L, connected with the eccentric-shifting mechanism, a gearwheel, n, meshing with the rack-bars m and L, and mechanism whereby said gear-wheel is rotated, substantially as set forth.

Vitness my hand this 13th day of November, 1888.

EDGAR M. BIRDSALL.

Witnesses:

JN0. J. BONNER, C. D. HoWE. 

